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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * File operations for Coda.
3 * Original version: (C) 1996 Peter Braam
4 * Rewritten for Linux 2.1: (C) 1997 Carnegie Mellon University
5 *
6 * Carnegie Mellon encourages users of this code to contribute improvements
7 * to the Coda project. Contact Peter Braam <coda@cs.cmu.edu>.
8 */
9
10#include <linux/types.h>
11#include <linux/kernel.h>
12#include <linux/time.h>
13#include <linux/file.h>
14#include <linux/fs.h>
15#include <linux/stat.h>
16#include <linux/errno.h>
17#include <linux/smp_lock.h>
18#include <linux/string.h>
19#include <asm/uaccess.h>
20
21#include <linux/coda.h>
22#include <linux/coda_linux.h>
23#include <linux/coda_fs_i.h>
24#include <linux/coda_psdev.h>
25#include <linux/coda_proc.h>
26
Adrian Bunkc98d8cf2006-03-24 03:15:53 -080027#include "coda_int.h"
28
Linus Torvalds1da177e2005-04-16 15:20:36 -070029/* if CODA_STORE fails with EOPNOTSUPP, venus clearly doesn't support
30 * CODA_STORE/CODA_RELEASE and we fall back on using the CODA_CLOSE upcall */
31static int use_coda_close;
32
33static ssize_t
34coda_file_read(struct file *coda_file, char __user *buf, size_t count, loff_t *ppos)
35{
36 struct coda_file_info *cfi;
37 struct file *host_file;
38
39 cfi = CODA_FTOC(coda_file);
40 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
41 host_file = cfi->cfi_container;
42
43 if (!host_file->f_op || !host_file->f_op->read)
44 return -EINVAL;
45
46 return host_file->f_op->read(host_file, buf, count, ppos);
47}
48
49static ssize_t
50coda_file_sendfile(struct file *coda_file, loff_t *ppos, size_t count,
51 read_actor_t actor, void *target)
52{
53 struct coda_file_info *cfi;
54 struct file *host_file;
55
56 cfi = CODA_FTOC(coda_file);
57 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
58 host_file = cfi->cfi_container;
59
60 if (!host_file->f_op || !host_file->f_op->sendfile)
61 return -EINVAL;
62
63 return host_file->f_op->sendfile(host_file, ppos, count, actor, target);
64}
65
66static ssize_t
67coda_file_write(struct file *coda_file, const char __user *buf, size_t count, loff_t *ppos)
68{
69 struct inode *host_inode, *coda_inode = coda_file->f_dentry->d_inode;
70 struct coda_file_info *cfi;
71 struct file *host_file;
72 ssize_t ret;
73
74 cfi = CODA_FTOC(coda_file);
75 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
76 host_file = cfi->cfi_container;
77
78 if (!host_file->f_op || !host_file->f_op->write)
79 return -EINVAL;
80
81 host_inode = host_file->f_dentry->d_inode;
Jes Sorensen1b1dcc12006-01-09 15:59:24 -080082 mutex_lock(&coda_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070083
84 ret = host_file->f_op->write(host_file, buf, count, ppos);
85
86 coda_inode->i_size = host_inode->i_size;
87 coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9;
88 coda_inode->i_mtime = coda_inode->i_ctime = CURRENT_TIME_SEC;
Jes Sorensen1b1dcc12006-01-09 15:59:24 -080089 mutex_unlock(&coda_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070090
91 return ret;
92}
93
94static int
95coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma)
96{
97 struct coda_file_info *cfi;
98 struct coda_inode_info *cii;
99 struct file *host_file;
100 struct inode *coda_inode, *host_inode;
101
102 cfi = CODA_FTOC(coda_file);
103 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
104 host_file = cfi->cfi_container;
105
106 if (!host_file->f_op || !host_file->f_op->mmap)
107 return -ENODEV;
108
109 coda_inode = coda_file->f_dentry->d_inode;
110 host_inode = host_file->f_dentry->d_inode;
111 coda_file->f_mapping = host_file->f_mapping;
112 if (coda_inode->i_mapping == &coda_inode->i_data)
113 coda_inode->i_mapping = host_inode->i_mapping;
114
115 /* only allow additional mmaps as long as userspace isn't changing
116 * the container file on us! */
117 else if (coda_inode->i_mapping != host_inode->i_mapping)
118 return -EBUSY;
119
120 /* keep track of how often the coda_inode/host_file has been mmapped */
121 cii = ITOC(coda_inode);
122 cii->c_mapcount++;
123 cfi->cfi_mapcount++;
124
125 return host_file->f_op->mmap(host_file, vma);
126}
127
128int coda_open(struct inode *coda_inode, struct file *coda_file)
129{
130 struct file *host_file = NULL;
131 int error;
132 unsigned short flags = coda_file->f_flags & (~O_EXCL);
133 unsigned short coda_flags = coda_flags_to_cflags(flags);
134 struct coda_file_info *cfi;
135
136 coda_vfs_stat.open++;
137
138 cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
Josh Triplett6ecbc4e2006-07-30 03:03:56 -0700139 if (!cfi)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141
142 lock_kernel();
143
144 error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
145 &host_file);
146 if (error || !host_file) {
147 kfree(cfi);
148 unlock_kernel();
149 return error;
150 }
151
152 host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC);
153
154 cfi->cfi_magic = CODA_MAGIC;
155 cfi->cfi_mapcount = 0;
156 cfi->cfi_container = host_file;
157
158 BUG_ON(coda_file->private_data != NULL);
159 coda_file->private_data = cfi;
160
161 unlock_kernel();
162 return 0;
163}
164
Miklos Szeredi75e1fcc2006-06-23 02:05:12 -0700165int coda_flush(struct file *coda_file, fl_owner_t id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166{
167 unsigned short flags = coda_file->f_flags & ~O_EXCL;
168 unsigned short coda_flags = coda_flags_to_cflags(flags);
169 struct coda_file_info *cfi;
170 struct inode *coda_inode;
171 int err = 0, fcnt;
172
173 lock_kernel();
174
175 coda_vfs_stat.flush++;
176
177 /* last close semantics */
178 fcnt = file_count(coda_file);
179 if (fcnt > 1)
180 goto out;
181
182 /* No need to make an upcall when we have not made any modifications
183 * to the file */
184 if ((coda_file->f_flags & O_ACCMODE) == O_RDONLY)
185 goto out;
186
187 if (use_coda_close)
188 goto out;
189
190 cfi = CODA_FTOC(coda_file);
191 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
192
193 coda_inode = coda_file->f_dentry->d_inode;
194
195 err = venus_store(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
196 coda_file->f_uid);
197
198 if (err == -EOPNOTSUPP) {
199 use_coda_close = 1;
200 err = 0;
201 }
202
203out:
204 unlock_kernel();
205 return err;
206}
207
208int coda_release(struct inode *coda_inode, struct file *coda_file)
209{
210 unsigned short flags = (coda_file->f_flags) & (~O_EXCL);
211 unsigned short coda_flags = coda_flags_to_cflags(flags);
212 struct coda_file_info *cfi;
213 struct coda_inode_info *cii;
214 struct inode *host_inode;
215 int err = 0;
216
217 lock_kernel();
218 coda_vfs_stat.release++;
219
220 if (!use_coda_close) {
221 err = venus_release(coda_inode->i_sb, coda_i2f(coda_inode),
222 coda_flags);
223 if (err == -EOPNOTSUPP) {
224 use_coda_close = 1;
225 err = 0;
226 }
227 }
228
229 cfi = CODA_FTOC(coda_file);
230 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
231
232 if (use_coda_close)
233 err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
234 coda_flags, coda_file->f_uid);
235
236 host_inode = cfi->cfi_container->f_dentry->d_inode;
237 cii = ITOC(coda_inode);
238
239 /* did we mmap this file? */
240 if (coda_inode->i_mapping == &host_inode->i_data) {
241 cii->c_mapcount -= cfi->cfi_mapcount;
242 if (!cii->c_mapcount)
243 coda_inode->i_mapping = &coda_inode->i_data;
244 }
245
246 fput(cfi->cfi_container);
247 kfree(coda_file->private_data);
248 coda_file->private_data = NULL;
249
250 unlock_kernel();
251 return err;
252}
253
254int coda_fsync(struct file *coda_file, struct dentry *coda_dentry, int datasync)
255{
256 struct file *host_file;
257 struct dentry *host_dentry;
258 struct inode *host_inode, *coda_inode = coda_dentry->d_inode;
259 struct coda_file_info *cfi;
260 int err = 0;
261
262 if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) ||
263 S_ISLNK(coda_inode->i_mode)))
264 return -EINVAL;
265
266 cfi = CODA_FTOC(coda_file);
267 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
268 host_file = cfi->cfi_container;
269
270 coda_vfs_stat.fsync++;
271
272 if (host_file->f_op && host_file->f_op->fsync) {
273 host_dentry = host_file->f_dentry;
274 host_inode = host_dentry->d_inode;
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800275 mutex_lock(&host_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 err = host_file->f_op->fsync(host_file, host_dentry, datasync);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800277 mutex_unlock(&host_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 }
279
280 if ( !err && !datasync ) {
281 lock_kernel();
282 err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
283 unlock_kernel();
284 }
285
286 return err;
287}
288
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -0800289const struct file_operations coda_file_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 .llseek = generic_file_llseek,
291 .read = coda_file_read,
292 .write = coda_file_write,
293 .mmap = coda_file_mmap,
294 .open = coda_open,
295 .flush = coda_flush,
296 .release = coda_release,
297 .fsync = coda_fsync,
298 .sendfile = coda_file_sendfile,
299};
300